LMU Seminars

MuFinder: A program to determine and analyse muon stopping sites

by Dr Benjamin Huddart (Department of Physics, Durham University)




Over the past decade there has been significant progress in calculating muon stopping sites using first-principles methods such as density functional theory (DFT). However, such calculations are still only carried out by a relatively small number of research groups and are not yet a routine part of analysing a muon-spin spectroscopy (µSR) experiment. Here I introduce MuFinder [1], a program that facilitates the process of calculating muon sites by allowing these calculations to be run through a graphical user interface, with the aim of making this procedure more accessible to users who are not necessarily experts in electronic structure methods.  I will demonstrate how muon site calculations can be carried out using MuFinder and then illustrate how they can enhance the interpretation of µSR experiments using examples from my research. First, I show how knowledge of the muon sites helps us to understand how the muon provides sensitivity to the unpaired spins in layers of the candidate quantum spin liquid material 1T-TaS2. In the second example, I show how DFT calculations of muon-stopping states provide evidence that the spontaneous local magnetic fields detected using muons in superconductors with time-reversal symmetry breaking (TRSB) are intrinsic to the TRSB superconducting state and not the result of a muon-induced perturbation [3].

  1. B. M. Huddart et al. arXiv:2110.07341 [cond-mat.str-el].
  2. S. Mañas-Valero et al., npj Quantum Mater. 6, 69 (2021).
  3. B. M. Huddart et al. Phys. Rev. Lett. 127, 237002 (2021).
Organized by

Zaher Salman

Zaher Salman